Shibendu Saha’s aunt Anita is brought to Charu Market police station on Monday morning. She and her husband Amalendu were denied bail in court and remanded in police custody till July 27. Picture by Pabitra Das

The first hint of suspicion that there was more to the tragedy at 91/3C, Tollygunge Road than had met the eye on Sunday lay embedded in the documents gone “missing” from the secure confines of the almirah on the second floor of the Saha home.

The most vital missing link was, of course, the “deed”.

According to sleuths, the document in question was the one that bore the seal of agreement between two brothers — Nabendu Bikash Saha and Amalendu Bikash Saha — who oversaw the wholesale trading of commodities in the joint-family business.

Apart from the details of the contract, the “deed” was the only piece of paper that had clearly spelt out the profit-sharing rules between the two partners.

With Shibendu suggesting that his uncle — Amalendu — had siphoned off a chunk of the little profits that their business yielded, the deed remains a key document for the detectives to get to the bottom of the case.

But curiously, this deed was nowhere to be found on Monday. “We have combed the entire flat for this deed. Ornaments and other items, including a few family photographs, lay intact inside the almirah locker. But the deed was missing,” confirmed an officer on the case.

As theories flew thick and fast on why and how the deed went missing, the detectives dug out several unanswered questions from Saturday night’s six killings and a suicide.

The first point of confusion: *the presence of a half-empty bottle of alcohol, but there being no trace of alcohol in the dead bodies.

“The post-mortem report shows no trace of alcohol in Shibendu. It appears someone tried to mislead the investigators by planting the bottle. It was as if to suggest that the man (Shibendu) had consumed alcohol before going on a killing spree. But that is not the case,” said an officer of the Charu Market police station.

There are several other mystery points, too.

• Sleuths probing the case wonder why information about the deaths reached them so late. The alarm was raised around 8.30 am, by a shrill cry from Soma Das, the maid in the Saha home. The local thana was informed around 9 am.

• “Also, it just can’t be that all the beds had their covers spread so neatly. Even the bodies were covered carefully, as if to make it appear that the assailant went about his job meticulously. But this is not possible even for a hardened criminal,” said an officer of the detective department’s homicide section.

• While Soma remains beyond the spectrum of doubt — Shibendu has suggested as much in the suicide note — the detectives are wondering why she did not wake up before 8.30 am on a Sunday morning. If she was drugged, then who did it'

• The post-mortem report reveals that the victims were killed at different times through Saturday night. While some were poisoned, others were throttled and two were even beaten on their head by a blunt object.

“So at least in one of the three rooms, there was a scuffle. Why did no one hear a thing'” the sleuths asked.

• And finally, ask the police, why were there marks of assault on the private parts of Swati, Shibendu’s wife'